Hence the whole Manosphere/Men Going Their Own Way that has appeared over the last few years. It boils down to societal changes in relationships. Many women have become very entitled due to social media and online dating, and chase the top few men (who don't settle down because they have loads of women chasing after them). Other men who don't get a chance are realising that society and marriage tends to be very lopsided against men. Why work hard to support a wife and kids, when half of marriages fail, and 80 percent of those are where women initiate the divorce. The man loses his money, house, kids and relationship, even if the wife cheats.
Some men go full monk and just enjoy their own lives, others have relationships with women, but it boils down to not validating your life though a relationship, and not putting yourself in the position of only being valued for what you provide, and in a position where all of that can be taken away from you. Relationship dynamics have become lopsided, and men are refusing to engage with the game rather than lose because it's weighted against them.
That's not to say there aren't great people out there (both men and women), but I'm sure we all see or experience relationships that fall apart because it's easier than working to save them. The family/relationship/dating dynamic has changed in many ways, and men in particular are finding it no longer works for them, and that they can be much happier being single, maybe dating, but not committing to anything more because they've realised that their lives are happier and more fulfilling that way. For more and more men, the risk of losing everything to a system that consistently works against them in the event of a relationship breakdown simply isn't worth participating in.